Anode for primary galvanic cell



Aug. 11, 1953 I R. c. SUNDEEN 2,643,718

ANODE FOR PRIMARY GALVANIC CELL Filed Feb. 23, 1950 INVENTOR ROY C.SUNDEEN A'TTORNEY Patented Aug. 11, 1953 ANODE FOR PRIMARY GALVANIO CELLRoy Carl Sundeen, Lakewood, Ohio, assignor to Union Carbide and CarbonCorporation, a corporation of New York Application February 23, 1950,Serial No. 145,723

4 Claims.

This invention relates to primary galvanic cells and refers moreparticularly to the manufacture of metal anodes for such cells.

The conventional cylindrical primary galvanic cell, the dry cell, ofcommerce comprises a zinc anode which serves also as the container ofthe cell. since the zinc anode is consumed during use of the cell, thistype of construction is undesirable from many standpoints. For instancean excess of zinc over that required by the cell must be provided forthe purpose of containing the non-consumable elements of the cell. Alsosufiicient zinc must be provided to prevent leakage of liquid from thecell.

It has long been recognized that the use of a consumable electrode as acell container is something less than ideal and from time to timesuggestions have been advanced for ways of avoiding such construction.One of such suggestions is that the anode be placed inside the cell andthat a non-corrodible container be employed. For instance, U. S. Patent1,267,349 suggests that the anode be made of sheets of zinc assembled soas to form an X-shaped member which could be placed internally of thecell. However, by reason of manufacturing difficulties the suggestedconstruction proved less economical and less practical than theconventional construction. Furthermore the anodes so made have beenunsatisfactory by reason of mechanical weakness or a tendency toexcessive local corrosion or both and the suggestion has come to naughtas have other similar suggestions.

It is the principal object of this invention to provide an improvedmethod of making a metal anode for rimary galvanic cells which anode isto be placed internally of the cell. Another object of the invention isa unitary anode for primary galvanic cells.

The invention by means of which these objects are attained comprises amethod of forming a unitary anode from a sheet of metal by a series ofcutting and bending operations explained in detail below and alsoincludes the anode so formed, which anode comprises a plurality(preferably four) of radially disposed vanes connected by a yoke havinga fiat area for terminal connection.

In the accompanying drawing:

Fig. 1 is a diagrammatic representation of a sheet of metal from which aplurality of anodes is to be formed;

Fig. 2 is a view of an anode blank cut from the sheet of Fig. 1;

Fig. 3 is a view of the blank of Fig. 2 after a bending operation;

Fig. 4 is an elevational view of a completed anode part beingbroken-away;

Fig. 5 is a perspective view of a completed anode; and

Fig. 6 is a horizontal sectional view of an anode according to theinvention provided with a bibulous wrapper.

In accordance with this invention a unitary metal anode may be preparedfrom a sheet or strip of metal of desired thickness by cutting a blankcomprising a plurality of plates joined together by a yoke which alsospaces the plates apart from each other. By a series of bendingoperations an anode having a plurality of substantially uniformly spacedradial vanes connected by the yoke which also provides a, site forterminal connection to the anodes may be prepared. For example, theblank may be bent in the yoke about axes perpendicular to thelongitudinal axes of the plates to bring the plates into proximity toeach other and about the longitudinal axes of the yoke or plates so asto V the plates, thus providing radial vanes. Although the yoke may bebent about its longitudinal axis over its entire length, this is notnecessary'and in general it is preferred not to bend the central part ofthe yoke.

Referring to the drawing by way of illustration, a plurality of blanks Bare cut, suitably by a repetitive stamping operation from a sheet S ofmetal of suitable thickness. Each of the blanks B has a pair of platesII), II spaced apart from each other but connected by a yoke section I2.The plates I0, II are bent about the lines a-a and a'a' (Fig. 2) in thedirection of the arrows to form vs (Fig. 3) but the central portion ofthe yoke I2 is preferably not bent in this operation. The plates I0, I Ihaving been bent into V-shape, the blank B is now bent in the yoke aboutthe lines bb, b'b' (Fig. 3) in the direction of the arrows to bring theapices of the Vd plates I0, I I into proximity to each other as shown inFig. 4.

By this procedure a metal 'anode having a plurality of vanes and asubstantially X-shaped cross section is formed in one piece from rolledsheet metal. By bending the yoke I2 as shown in Fig. 4 a flat section I3is formed which serves as a terminal for the anode. By bending theplates I0, II substantially the vanes of the finished anode areuniformly, radially spaced apart from each other, making for uniformconsumption of metal during use of a primary galvanic cell in which theanode is employed.

In accordance with conventional practice the active surfaces of theanode are enveloped by a bibulous separator or wrapper M of paper ortextile or other conventional material (Fig. 6) which is insoluble inelectrolyte, the surface of the wrapper next the anode beingconventional starch paste or paste substitute. All surfaces of the anodewhich Would otherwise come into contact with the depolarizer mix of acell should be covered by such wrapper. The wrapper may be provided atany convenient time during the formation of the anode and preferablyshould be so applied that there is no seam at the bottom edges of theanode.

The operations of the method of the invention are simple and lendthemselves admirably to the continuous manufacture of anodes and may beperformed by machines.

Since the anode produced by the method of the invention is one piece ofmetal, its performance in a cell is far superior to that of anodes ofsimilar design but made up of several pieces; there are no mechanicaljoints or solder-ed or welded connections and consequently nodiscontinuities which tend to cause mechanical weakness and excessivelocalized corrosion. Further, since it is possible to make the platesI'll, II only long enough to be completely covered by depolarizer mix ina cell, the only metal unusable electrochemically is that in the yoke12. This results not only in a saving of anode metal but also tends tominimize the difficulties caused by residual quantities of anode metalin contact with mix after the cell has delivered its normal service.

Oridinarily anodes for primary galvanic cells are composed of zinc. Themethod of the invention is especially Well suited to the manufacture ofzinc anodes because of the workability of zinc, but it is equallyadapted to use in making anodes of any desired metal or alloy.

Although for purposes of illustration the invention has been describedwith particular reference to the fabrication of an anode having fourvanes substantially 90 apart, it Will be apparent to those skilled inthe art that its principles are not limited solely to the manufacture ofthat particular form of anode. Furthermore the individual bending stepsof the method of the invention need not necessarily be performed in anyparticular order.

I claim:

1. A method of making a metal anode for a primary galvanic cell whichcomprises preparing a unitary blank comprising a plurality of platesspaced apart from each other and connected by a yoke and bending saidblank in said yoke about axes perpendicular to th longitudinal axes ofsaid plates and about the longitudinal axis of said yoke thus providinga plurality of substantially uniformly spaced radial vanes connected bysaid yoke.

2. A method of making a metal anode for a primary galvanic cell whichcomprises preparing a unitary blank comprising a pair of plates spacedlongitudinally apart from each other and connected by a yoke; bendingsaid plates along their longitudinal axes, thus forming each of saidplates into a V; and bending said blank in said yoke so as to bring theapices of said Vs into close proximity.

3. A method of making a metal anode for a primary galvanic cell whichcomprises preparing a unitary blank comprising a pair of plates spacedlongitudinally apart from each other and connected by a yoke; bendingsaid plates along their longitudinal axes about then forming each ofsaid plates into a V; and bending said blank in said yoke so as to bringthe apices of said Vs into close proximity.

4. A method of making a metal anode for a primary galvanic cell whichcomprises preparing a unitary blank comprising a pair of plates spacedlongitudinally apart from each other and con nected centrally of theirlongitudinal axes a yoke; bending said plates along their longitudinalaxes about 90 thus forming each of said plates into a V; and bendingsaid blank in said yoke so as to bring the apices of said Vs into closeproximity and substantially parallel to each other.

ROY CARL SUNDEEN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 368,608 Peyrusson Aug. 23, 1387 1,196,611 Tassin Aug. 29, 19161,266,166 Sangers :May 14, 1918 1,267,349 Smith May 21, 1918 1,631,568Yngve June 7, 1927 2,212,054 Spicer Aug. 20, 1940 2,250,233 ParkingtonJuly 22, 1941

